References:
This is an update of the above alog entries. After turning off the isolation loop for EX ISI, I started the initial alignment of the TMS, ITMX and ETMX again.
This was done by pointing TMS to ITM arm cavity baffle diodes PD1 and PD4 (note that for ITM baffle PD4 is connected to PD3, so the actual channel I looked at was H1:AOS-ETMX_BAFFLEPD_3_POWER), take note of the TMSX alignment slider values, set the TMS slider to the mean of PD1 and PD4, then align ITMX to point the beam to ETMX baffle diodes etc.
The bias sliders are calibrated using 4000m arm length and the vertical/horizontal distance between the PDs.
In the table below, (P, Y) refers to the alignment slider values for each optic, "Aligned" is the mean of PD1 and PD4
optic | TMSX | ITMX | ETMX |
PD1 (P, Y) | (109, -203) | (67, -80) | (322, -1) |
PD4 (P, Y) | (178, -266) | (99, -47) | (362, -71) |
Aligned (P, Y) | (143.5, -234.5) | (83, -63.5) | (342, -36) |
Slider calibration (P, Y) [urad/urad] | (1.04, 1.07) | (1.17, 1.14) | (0.90, 0.51) |
Note that HEPI still has 12000 counts RY offset to relieve TMSX PIT which is due to 300urad systematic in ETMX.
An error in the table, TMSX YAW = 1.14 urad/urad instead of 1.07.